Integrated circuit fabrication may involve formation of intersecting lines of material. A method for forming such intersecting lines is to first form intersecting trenches, and to then fill such trenches with the material. A problem encountered during the fill of the trenches is that more material is required to fill intersecting regions than is required to fill other segments of the trenches. Such problem is explained with reference to FIGS. 1 and 2.
FIG. 1 shows a construction 2 having a pair of intersecting trenches 4 and 6 formed within a base material 5. The trenches 4 and 6 intersect with one another at an intersection 7.
FIG. 2 shows the construction 2 after material 8 is deposited within the trenches 4 and 6. The material 8 is deposited to sufficient thickness to completely fill trenches 4 and 6. However, such thickness is not sufficient to fill the intersection 7, and accordingly a void 9 is left within the intersection. Such void can be problematic during subsequent processing, and accordingly it is desired to prevent formation of the void 9. Unfortunately, if sufficient material is deposited to completely fill the intersection and thereby prevent formation of void 9, then excess material is deposited within other segments of the trenches 4 and 6 which leads to waste of the material 8. Accordingly, fabricators of integrated circuitry are faced with the dilemma of either leaving voids (like void 9) within intersecting trenches during the fill of the trenches, or overfilling the trenches and thereby wasting material in order to prevent the void formation. Is desired to develop methods and structures which circumvent such dilemma.